Here's the ugly.
And the good.
The guppies slowly faded away, aided by the addition of new fish which promptly went belly-up, until we were left with three hardy specimens, all apparently male.
Last night I noticed one of them was seriously vast, and either badly constipated or deeply pregnant. Making mental notes to dig out the nursery net, I went to bed.
And this morning, lots of babies!
So I'm guessing conditions in the tank are finally sufficient to support growth, which is excellent. But is the alien insect thing going to eat all the fry?